MANN- DIATOMS OF THE ALBATROSS VOYAGES. 3t53 



Diatomaceen, « plate L, figur< 39, and Schmidt's Ulas, plate 2, figure 29. Ii also hap 

 considerable resemblance to Schmidt's Atlas, plate 2, figure 10, \ kUtoniana Schmidt, 

 which Cleve& makes a variety of A', approximates Grev.; though how he i 

 approximata in that form and A', lyra in the form figured by Janisch jusl mentioned is 

 beyond my understanding. Whether or nol the form represented by Janisch's figure, 

 the V. bittoniana of Schmidt, and m\ Bpecimen should be classed as a v ariety of x > 

 is a question of the Limits of a species and th< dissimilarity il is desirable to 



include under one name. Taking the view thai it is advantageous to add as few new 

 forms as possible to the already enormous Bpecies A lyra, I have given the above 

 nam.'. For reasons mentioned in the introduction, the naming of varieties is nol 

 favored by the writer. Ii may be noted thai my specimen differs in several respects 

 i"n.iii the two I have here associated with it, especially in the H-shaped hyalim - 

 doI having its i ips approach, bu1 strictly parallel, whereby the central rows of striae 

 are of the same width from the apices to the center. Bui the minor differences between 

 my form and thai of Janisch's above can nol make them two species. 



Type in the U. S. National Museum, No. 590149, from station 2920H, Hawaiian 

 Islands, November 21, L89 1 ; 570 fathoms, bottom of brown mud and fine sand. 



Navicula sandriana Grun. Verh. Zool. Bot. Ges. Wien 13: 153. pi. 13./. 5. L863. 



Schmidt, Atlas pi. 3. f. 10. L875; pi. 70. f. 45. L881. O'Mea Pi Roy. Irish 



Acad. II. 2: 388. pi., L875 figure poor . Lagers. Bih. Sv. Vet. Akad. 



Handl. 3 13 : 41. 1876. De Toni, Syll. Alg. 2: L05. L891. Cleve, Sv. Vet. Akad. 



Uaii.ll. 27 : 59. L8 

 cula rimosa Grev. Trans. Micr. Soc. Lond. n. s. 14: L29. pi. 12. f. 25 



Moeb. Diat.-taf. pi. 75. f. 15. 1890. 

 1 1 seems to me the • -riLrinal figures of both the above give emphasis to a rather incon- 

 Btanl feature of this diatom, namely, the narrow sickle-shaped Line of striae midway 

 between the center and the margin. Tin- i- very Liable to be reduced t" a somewhat 

 indefinite granulation blending with the more indistind granulation about it. In 

 fact, there an- unmistakable varieties in which these sickle-shaped Lines can virtually 

 disappear. Ln such a case we are confronted by the question in what respeel such a 

 form i> separable from varieties of A. hennedyi and A". . aor can we find any 



satisfactory answer. In othei words, however useful for classification it undoubtedly 

 is to retain tip- enumerated names to designate tie- more diverse of tin-.- forms, it is 

 probable thai both N.sandriana and A', hennedyi will eventually be considered only 

 striking varial ions of A", prat U tta. 



Found at station 4516H, Gulf of 1 'alifornia. 



Navicula silicula Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1841: 419. 1843; Mikrog. 



!>1. 6. I.J. 16, pi. 10. I.f. 13, pi /../. .'.'. pi. UA.f. 87a b. L854. Pritch. Bist. 



Enfus. ed. 4. 894. L861. 

 Navicula limosa Kutz. Bacill. KM. pi S.f. 50. L844. Grun. Verh. Zool. 



Wien 10: 544. pi 3. f. 8a c, 10 nol I860. Donk. Quart. Journ. 



Micr. Sci. n. s. 9: 294. pi is./. 7. L869. Moeb. Diat.-taf. pi 79. f. 7. 1890. 



Donk. Brit. Diat. 73. pi 12. f. 6. L871 ::;. Brun, Diat. Alp. 7:i. pi :./. 12. L880 



Van Ilcr. Synop. L03. pi 12. f 1881; Treat. Diat. 219. pi 



- L896. Lagers. Bih. Sv. Vet. Akad. Bandl. l u : 31. pi l.f. 6, 7a. L873. 



Rabh. Sussw. Diat. 41. pi >../. 31. L853. Pritch. Bist. [nfus. ed. l. B94. L861 



DeToni, Syll. Alg. 2: L47. 1891. 

 Navicula silicula Grun. ; Van Beur. Synop. pi 12. f. :i. L881. 

 Caloneis silicula Cleve, Sv. Vet. Akad. Bandl. 26-: 51. L894. 



oJahresb. Komm. Deut. Meere 2: ,>l. l. f.39. L874. 

 6 Loc. cit. 



